Resource heterogeneity structures aquatic bacterial communities.
Muscarella ME, Boot CM, Broeckling CD, Lennon JT
ISME J. May 2019. doi: 10.1038/s41396-019-0427-7
COMMENT: This study tries to address whether and how heterogeneity of resources can affect the composition of bacterial communities in aquatic environments.
The research has taken into account both the resource composition and the concentration that could influence the bacterial populations in the surface waters of several lakes in North America.
The dissolved organic matter in the samples was studied as a representative of the resources that bacteria can use to grow and survive. The composition of this matter was chemically analyzed to address both its heterogeneity and concentration. These results were crossed with those from microbial communities’ composition and diversity.
The lakes served as good representatives of a range of conditions that could affect patterns of bacterial diversity with more than 700 components detected, 37% dissimilarity among the lakes studied and more than 170 chemically heterogeneous influential components. The composition of the bacterial communities also varied between lakes.
These data were statistically analyzed to try to explain the relationships between resources and bacterial communities. Resources heterogeneity contributed in more extent to bacterial diversity than resources concentration. Generalist bacteria were common in many samples, but this does not limit the role of resource heterogeneity. Apart from the fact that generalists also have preferences in resources usage, this work has also found evidence of the existence of resource specialists.
The authors propose that the type of bacteria (generalists versus specialists) and the availability of resources determine the type of response to changes in resources heterogeneity.
As a whole, this work is a good example of how the use of genomic studies to identify bacterial populations can serve to address complex ecology studies.